DIAZOBENZENE SULPHATE l6r
ing, is filtered and washed with a little water. It is then'warmed
gently for a few minutes with dilute caustic soda solution. The
base is liberated, filtered, washed with water and recrystalHsed
20 S(N H CUH6)., + H Cl = CS N CuHfi -f C. N H CCH6. H Cl + H.S
Thujeaihanilide. Pheiiyl Mustard Triphenylguanidine
Properties.—Colourless needles ; in. p. 143°.
Reaction. — Boil for a short time with moderately strong
caustic soda solution. Aniline is formed.
See Appendix) p. 281.
PRKPARAT JN 62. :
Diazobenzene Sulphate. C-Hr-N.SCXH
(iriess, Anualen, 1866, 137, 76 ; Knocvcnagel, Bcr., 1895, 28,
15 gnus, aniline.
140 „ (175 c.c.) absolute alcohol.1
30 „ (16 c.c.) cone, sulphuric acid.
20 „ amyl nitrite.
Mix the aniline and alcohol and add the concentrated
sulphuric acid in a slow stream with constant shaking. The
precipitate of aniline sulphate, which first appears, reclissolves.
Cool the mixture to 30'' and keep at 30—35° (thermometer in
the liquid) and out of direct sunlight whilst the amyl nitrite is
dropped in from a tap-ftmnd. Then cool in ice water, and
leave for half an hour. The dia/obenzene sulphate separates as
a colourless or pale green mass of needle-shaped crystals.'** It-
is filtered at the pump and washed with a little alcohol.
Although diaxobenzene sulphate is much more stable 'than the
1 Neither methylated spirit noi' methyl alcohol can be substituted.
COHEN'S ADV. p. o. c. M